Ryan Fitzgerald, DPM PRESENT RI Associate Editor Hess Orthopedics & Sports Medicine, Harrisonburg, Virginia

By Ali Abadi, DPM, Jennifer Berlin, DPM and Warren Mangel, DPM
Dr Ali Abadi
West Jersey Virtua Hospital, New Jersey.
[email protected]

The case of a 42 Year-old female with persistent pain and numbness in the left foot and ankle. Magnetic resonance imaging showed a ganglion cyst communicating to a cystic region within the tibia bone. The patient was treated with surgical excision of the mass, curettage of the tibia and packing with bone chips. At excision, the ganglion was confirmed to be communicating with the left distal tibia bone.

The term ganglion was first used by Hippocrates to designate a knot of tissue filled with “mucoid flesh”. It is a cystic swelling,1-3 cm in diameter, found typically in close proximity to joints and tendon sheaths. The most common sites are the dorsal and volar aspect of the wrist, the dorsum of the foot, and around the ankle and the knee.(1) These lesions are well demarcated,movable within the surrounding tissue, and often loosely attached to a tendon sheath or the capsule of a joint. The dense fibrous capsule enclosed cysts contain a viscus, jelly-like fluid, rich in hyaluronic acid and other acid mucopolasaccharides.(2)

CASE REPORT

HPI: A 42 year-old female presents with severe pain in her left foot and ankle with intermittent numbness in the toes of the left foot. The patient states that she has mild pain while ambulating and going up the stairs, and denies any history of trauma. 

PE: Physical examination reveals (Fig1) positive pain on palpation around the posterolateral aspect of the patient’s left ankle and she has numbness to her toes.

Radiography: Plain radiograph reveal moderate increases in soft tissue swelling around the lateral malleolus (Fig2). However, there is no evidence of ankle osteoarthritis, fracture, or other osseous abnormality.

X-ray studies are negative for stress fracture or other obvious osseous abnormalities.

Labs and Other Diagnostic Tests: Laboratory examination included corpuscular blood count with differential, white blood cell count, rheumatoid factor, C-reactive protein, erythrocyte sedimentation rate, and serum uric acid were all unremarkable. EMG result was negative for sciatica.

Conservative Treatment: Conservative treatment was initially attempted to relive symptoms, consisting of woral anti inflammatory medication and ankle bracing for stabilization, but were found to be ineffective

Other Imaging: Magnetic Resonance Imaging (MRI) of the foot and ankle was ordered.

MRI of the ankle revealed a cystic lesion of 3cm x 1.5 cm in diameter with tibial bone erosion. Sagittal views showing a well defined homogeneous bright signal in T2 (fig 3b) and decreased signal in T1 (Fig 3a), extending to the posterolateral distal Tibia.(3)

Surgical Procedure

Surgical excision was performed. After inflating the thigh tourniquet, the ganglion cyst was excised through a 7 cm posterolateral incision. (Fig1). The mass was separated from the surrounding Flexor hallucis longus muscle and tissues. There was a well-defined capsule. The cystic mass was 3cm x 1.5 cm (Fig 4a-f), and it was noted to have penetrated the tibia. The bone defect was cleared out and it was packed with bone chips. The tibial bone defect was about 1 cm. deep (Fig 5a, 5b).

The pathology report was consistent with the diagnosis of ganglion. The cyst wall was 0.1 cm thick and was composed of collagenous connective tissue and it presents along with several islands of mucinous material." No epithelial lining was noted. No evidence of neoplasm, inflammation or granuloma.

Postoperatively, the patient is pain-free and shows normal strength and sensation in the left foot and ankle. No recurrence has been noted up until the writing of this report.

Figure 1:  Left leg with surgical mark.	Figure 2: Lateral radiograph ,left foot and ankle.
Figure 3a: Sagital view MRI. 2009	Figure 3b
Figure 4a	Figure 4b: Intra-operative photograph showing the ganglion cyst intact
Figure 4c: Intra-operative photograph showing the ganglion cyst intact	Figure 4d: Intra-operative photograph showing the ganglion cyst intact
Figure 4e: Intra-operative photograph showing dissected cyst.	Figure 4f
Figure 5a: Intra-operative photograph showing tibial erosion. (Covered)	Figure 5b: Intra-operative photograph showing tibial erosion. (exposed)

Discussion

The ganglion cyst is probably the most common soft tissue mass found in the foot and ankle.4 It is also a common occurrence in hand or wrist. A ganglion is a well-circumscribed, soft, and fluid-filled cystic mass that is frequently freely movable in the subcutaneous tissues and most often is found on the dorsum of the foot.4 The exact etiology is unknown; however, traumatic, degenerative or inflammatory process in adjacent joints has been suggested as possible etiological factors.(3)

Magnetic resonance imaging is the modality of choice in the assessment of soft tissue tumors.5 On MRI  images, ganglion cysts demonstrate low intensity on T1 and high signal intensity on T2 weighted images. Although 75% of all biopsy-proved soft tissue masses of the foot and ankle are benign, ganglion cysts should be differentiated from other tumors such as lipoma, hemangioma, infection and malignant tumors, such as malignant fibrous histiocytoma.(6-8)

References

1. Carp, L. and Stout, surgery, ,47,460. 1928
2. Soren,A. Clinical Orthopaedics , ,48,173. 1966
3. Crim, Julia R., Cracchiolo A., Hall R., Imaging of the Foot and Ankle, 219,1996
4. Hattrup SJ, Amadio PC,Sim FH et all,Metastatic tumors of the foot and ankle.FootAnkle, ,8:243-247,1988
5. Steiner E,steinbachh LS, schnarkowski P,Ganglia and cyst around joints, Radiol Clin North Am,1996,34:395-425.
6. Llauger J,Palmer J,Monill JM, Franquet T,Bague S,Roson N. MR imaging of benign soft –tissue masses of the foot and ankle.,1481-98,1998
7. Pontius j,Good J,Maxian S., Ganglions of the foot and ankle,an retrospective analysis of 63 procedures. J Am pod Assoc. 89-164, 1999.
8. Downey, M et all, McGlamry’s Foot and ankle text book,1354-1366,2001.

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